Catalytic performances of CuGa and CuSn binary oxide catalysts towards N2O decomposition and reduction

Direct catalytic decomposition of N2O in inert and oxidative atmosphere was investigated over two series of binary oxide catalysts containing CuO coupled with Ga2O3 or SnO2 dispersed over a silica-alumina support (CuGa/SA and CuSn/SA series catalysts). The activity for N2O decomposition in the absence of oxygen was between 0.1 and 0.2 mu mol g(cat) s(-1) in the 500-600 degrees C interval over the CuSn/SA series catalysts with conversion between 80 and 90%. Lower activities with larger differences were observed within the CuGa/SA series catalysts. The presence of oxygen in the feed (O-2/N2O ratio up to 20:1) did not affect the activity of the CuGa/SA series while a light decrease of activity could be noticed on the CuSn/SA series. The effect of methane reductant in the selective N2O reduction (N2O-SCR) was tested. On the CuGa/SA series samples, the best reaction selectivity was observed.